http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
A study on stability analysis of biochemical reaction system with negative feedback regulation
Takashi Nakakuki 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10
In this paper, stability of a biochemical reaction system with negative feedback regulation is considered. It is well known that such a system induces a Hopf bifurcation depending on an input level or kinetic parameters. Although the eigenvalue analysis is a powerful method for evaluating the bifurcation and the stability, applying the method to a highdimensional system with many nonlinear rate equations would be a troublesome task in model-based analysis since many hand-calculations of partial differentiation are needed to obtain a Jacobian matrix. Then, a simple and straightforward method based on Nyquist criterion is proposed. The method is a kind of describing function method, and the vector locus for the Nyquist criterion is drawn computationally by performing frequency response test for equivalent transfer function of the open loop system.
Linear time-varying modeling of inter-organ regulatory system
Daisuke Eto,Takashi Nakakuki,Jun-ichi Imura 제어로봇시스템학회 2022 제어로봇시스템학회 국제학술대회 논문집 Vol.2022 No.11
In this study, we propose a linear time-varying model of the inter-organ regulatory system. It is well-known that the regulation of energy metabolism is highly controlled by complex metabolic pathways coupled among various organs. On the other hand, a malfunction of this regulatory system can induce various pathological conditions related to the metabolic syndrome, implying that homeostasis of energy expenditure in the inter-organ regulatory system can be treated as a control problem, given an appropriate mathematical model. Moderately abstracting the complex mechanisms and maintaining the comprehensiveness of the inter-organ networks, we construct a simple model comprised of 16 states and 31 rate equations. Since our model is described as a linear time-varying system, it is expected that various control theories can be applied for the model-based analysis of the inter-organ regulatory system.
Development of drinking support device for spinal cord injuries to enhance quality of life
Ayano Tanishima,Takashi Nakakuki,Hiroto Noguchi,Takashi Kanamaru 제어로봇시스템학회 2013 제어로봇시스템학회 국제학술대회 논문집 Vol.2013 No.10
Spinal cord injury causes a paralysis of any part of the body depending on which part of spinal cord is destroyed. It is well known that a severity of the paralysis is determined by both a location and a degree of injury in the vertebral bones. For example, in a case of injury at the C4 vertebral bone a patient is paralyzed from the neck down, and needs a caregiver to help almost all activities of daily life. Recently, a quality of life is considered to be important, and various welfare devices have been proposed to realize a better life of a patient. Regarding a C4 patient, drinking water by oneself whenever he/she wants to do is strongly desired in the daily life. In this paper, we develop a drinking support device for a C4 patient. The device is evaluated in a rehabilitation hospital, and it is shown that all requirements on structure, degree of freedom, safety, conform, daily maintenance, etc. are satisfied with an acceptable level.
A study on a waist power assist suit for a caregiver to prevent lower back pain
Yoshitoshi Ikeya,Takashi Nakakuki 제어로봇시스템학회 2013 제어로봇시스템학회 국제학술대회 논문집 Vol.2013 No.10
We currently develop a waist power assist suit for a caregiver that physically supports his/her lifting and twist motions to prevent lower back pain. In our earlier studies, a DC motor-driven mechanism has been proposed where two motors that are attached at both sides of lower back generate the assistive torque for a lifting motion by driving them in the same direction, and for a twist motion by driving them in different directions. In this paper, we address to reduce the suit weight, refine the design, and to improve how to put on the suit. Regarding a signal processing for motion recognition, we also have studied a surface EMG-based signal processing with support vector machine. Although the recognition rate with the sensing system is promising off-line, the algorithm is quite complicated for implementation to a microcomputer. In this paper, we propose a simple signal processing for motion recognition based on surface EMG.
Design method for biomolecular circuit with plasticity
Kenta Hidaka,Takashi Nakakuki 제어로봇시스템학회 2021 제어로봇시스템학회 국제학술대회 논문집 Vol.2021 No.10
In this paper, we propose a design method for a biomolecular circuit that can dynamically change its function according to repetitive input stimuli. In DNA computing, which involves the construction of a DNA reaction system that executes desired information processing, the circuit function strongly depends on the network structure and reaction rate parameters of the chemical reaction system. In other words, it is necessary to design a DNA circuit specialized for a specific circuit function. We aimed to achieve “plasticity” of the DNA circuit by addressing the motivating example; for a two-input one-output DNA circuit, its function is initially YES logic but turns to OR logic as the repetitive input stimuli are given. Our proposed method was verified by numerical simulations based on reaction kinetics while utilizing dependable computer-aided software.
Frequency Response Analysis of Large-Scale Biological Systems
Takaaki Moriyama,Takashi Nakakuki 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10
In this paper, we propose an analysis method for a complicated and huge biological system. As a target system, we employ a newly published signal transduction system with transcriptional control. Our method is based on a extension of frequency response analysis. Since an output response depends on both frequency and amplitude of input signal, we straightforward construct a Bode-like diagram using three-dimensional space regarding frequency, amplitude and evaluation value. We also propose that a ratio of L2 norms between input and output signals is good to use for an evaluation value.
Frequency Analysis of intracellular signal transduction systems
Hiroki Ishiyama,Takashi Nakakuki,Chiharu Ishii,Mitsuo Kobayashi 제어로봇시스템학회 2010 제어로봇시스템학회 국제학술대회 논문집 Vol.2010 No.10
In this paper, we propose two analysis methods for a complicated and huge biological system. As a practical biological system, we employ a newly published signal transduction system with transcriptional control. For such a system, only few analysis tools such as parameter sensitivity analysis are available. First, we extend the concept of Bode diagram, including the effect of changes of both amplitude are frequency of input signal on output response. Next, we introduce the calculation of the L2-induced gain. Although it is difficult to find the nominal gain theoretically, we show that the distribution of the gain over various amplitudes and frequencies of input signal provides us some useful information in a biological system.
Development of a particle simulator on cancer cell signaling network with PC cluster system
Makoto Ogawa,Takashi Nakakuki,Chiharu Ishii,Mitsuo Kobayashi 제어로봇시스템학회 2010 제어로봇시스템학회 국제학술대회 논문집 Vol.2010 No.10
In various cancer cells, over-expression or mutation of epidermal growth factor (EGF) receptors is experimentally observed, and induces abnormal activation of intracellular signaling proteins, followed by continuous cell proliferation via dysfunctional gene regulatory networks. Since the activation process of EGF receptors on cell membrane is complicated and not fully understood, it is still a challenging work to develop the mathematical model from the viewpoint of cancer therapy such as drug discovery. In this paper, we develop a particle simulator on EGF-induced activation of EGF receptors on cell membrane. The engine of our simulator is based on the Hybrid Null-event Monte Carlo algorithm. The advantage is that our simulator is capable of evaluating “lateral signaling” of EGF receptors, and directly comparing to the corresponding experimental data that shows a distribution of activated EGF receptors.
Stability Analysis of Wnt-ERK cellular signalling by using Nyquist Criterion
Taisei Hidaka,Takashi Nakakuki 제어로봇시스템학회 2017 제어로봇시스템학회 국제학술대회 논문집 Vol.2017 No.10
We have previously reported an analysis method for intracellular signal transduction systems by using Nyquist criterion in which we provided a proof-of-principle study with the Goodwin oscillator as a simple model that is a threedimensional small system with a negative feedback regulation. In this study, we try to apply our method based on Nyquist criterion to a practical cancer cell signalling model on the Wnt-ERK pathway that is a 31-dimensional ordinary differential equation system with the six multiple feedback regulations. In this study, two different feedback loops that are mediated by a same signalling molecule are investigated. By applying our method to the analysis of each feedback loop independently, the effect of them on the stability of the whole system is compared.